package main.java.indi.zyj.hot100;

import main.java.indi.zyj.hot100.base.ListNode;

public class MergeTwoLists {

    public ListNode mergeTwoLists(ListNode list1, ListNode list2) {
        ListNode p1 = list1, p2 = list2;
        ListNode head = new ListNode(-1);
        ListNode p = head;

        while (p1 != null && p2 != null) {
            if (p1.val <= p2.val) {
                p.next = p1;
                p1 = p1.next;
            } else {
                p.next = p2;
                p2 = p2.next;
            }
            p = p.next;
        }

        if (p1 != null) {
            p.next = p1;
        }
        if (p2 != null) {
            p.next = p2;
        }

        return head.next;

    }
}